Septra DS   (U.S.N.L.M.)
Dosing Mild/Moderate: 1 single strength tab(400mg/80mg) q12hr, 10-14 days.    
1 DS tab(800mg/160mg) q12hr, 10-14 days.
Chem Specs sulfamethoxazole / trimethoprim
Quantities DS = 800mg sulfamethoxazole/160mg trimethoprim, (low strength also available 400mg/80mg)
Cost 16.93 / 20 tab generic
Class Sulfonamide / Polypeptide (Pyrimidine (DHFR inhibitor))
Action Sulfonamides inhibit bacterial folate synthesis.
Trimethoprim is a DHFR* inhibitor so inhibits bacterial DNA synthesis.
Usage Used for soft tissue infections:
hordeolum, preseptal cellulitis, dacryocystitis and dacryoadenitis.
Used when Penicillin allergy is known or suspected, for infections resistant to
other medications, when MRSA is suspected and for health care personel.
Contraindications Allergy to sulfamethoxazole, trimethoprim, or any sulfonamide.
Severe liver or kidney disease.
Pediatric use Contraindicated in children less than two months of age.
Consult dosing tables (package insert ) and warnings for children under 40kg.
Pregnancy Category C (N.I.H.)    Teratogenicity demonstrated in rats in some studies.
Increased risk of spontaneous abortion suggested in one large human study.
(Also avoid use with nursing mothers)
Also labeled Bactrim and Sulfatrim.
May increase risk of Stevens Johnson Syndrome.
*Dihydrofolate reductase acts to reduce dihydrofolic acid (DHF) to tetrahydrofolic acid, a precursor in the thymidine synthesis pathway of DNA synthesis.     N.L.M. DailyMed page for Septra DS          PDR page for Septra DS